This invention relates to weapon systems and in particular to apparatus for feeding either linked or linkless rounds to a rapid-fire weapon. While the invention is described in particular detail with respect to the linkless ammunition in a rapid-fire weapon system, those skilled in the art will recognize the wide applicability of the principles disclosed hereinafter.
Rapid-fire weapon systems, particularly when installed in an air-borne carrier, present heretofore unresolved problems in their operation. In general, the firing weapon of an air-borne carrier is contained in a gun mount or turret located at one part of either a fixed or rotary wing aircraft, and the magazine supply for ammunition rounds is located some distance from the gun mount in another part of the aircraft. Mere separation of the weapon and magazine is troublesome. For example, the length of the supply line between the magazine and the weapon can be so great that the pulling force of the weapon may be insufficient to draw the rounds from the magazine container due to the conveyor length, and, hence, the weight of the conveyor along the supply path.
The prior art does deal with the conveyor length problem and offers a number of problem solutions. In general, the prior art provides means for driving either the magazine or the conveyor at a rate comparable to the weapon demand rate. While these prior art solutions work for their intended purposes, the solution themselves often raise additional difficulties. Thus, high power is required to overcome the inertia of the magazine when the magazine is driven in conjunction with the demand rate of the weapon. Since the firing weapon demand rate varies between instantaneously high and instantaneously low, depending on whether the firing mechanism is held on or released, rather complex systems are needed to bring the mazazine first to a high feed rate and then to bring it to rest after the gun shuts down. Magazine drive is further complicated when the weapon is fired in short but repeated bursts. Extremely complex devices are required for drive control under these conditions. If the magazine itself is not drivable, some form of powerdriven sprocket is utilized in conjunction with a stationary magazine to accomplish the same purpose. Although a power driven sprocket requires less driving power, it requires the same type of complex control devices. Other weapon system designs rely merely on the pull of the gun to move the rounds to the firing chamber.
While prior art solutions to the problem of feeding a rapid-fire gun are acceptable in certain application installations, their use with a rapid-fire weapon movable in elevation and azimuth planes, for example, particularly where the system is installed in an air borne carrier, has presented additional unresolved difficulties. In air borne weapon applications, individual rounds from the magazine are transported to the gun mount by some type of conveyor or other rounds carrier, usually contained within a flexible chute. These flexible chutes commonly are capable of motion in both elevation and azimuth planes. The chute contortions dictated by required elevation and azimuth angles for proper gun mount flexibility result in ever changing dynamic conditions in the ammunition, chutes and conveyors. This in turn has resulted in increased weapon reliability problems, because flexible chutes have a number of inherent deficiencies. For example, friction between the conveyor or the ammunition proper and the feed chute can vary as the chute twists and rolls or expands and contracts in following the motion of the weapon. Consequently, the force required to either drive or pull the ammunition varies, and changes the power requirements for the drive mechanism. Because of the motion of the weapon necessarily acts on the flexible chute utilized, the chute may collapse or extend axially during weapon motion. Compression or extension causes the ammunition flow path to change its dimensional length, which generally leads to a compressive or tension force being applied to the conveyance means or the ammunition. Compression or tension forces on the chute leads to dimensional changes in the chute which in turn causes a velocity change for the ammunition within the feed chute. Compression and tension forces on the chute, in addition to increasing the friction between the ammunization and chute, also can cause separation of either the ammunition conveyance means or the chute itself.
Most prior art weapon systems utilize a common power source both to power the weapon's storage magazine and to power the associated feed system components in order to match the velocity and acceleration requirements of the firing weapon. Commonly, use of a common power source leads to utilization of oversized power devices in order to meet all system contingencies and complex control means for regulating the power source. This combination of factors leads to increased weight, inertia, complexity and expense of the weapons system.
The invention disclosed hereinafter overcomes these prior art deficiencies with a novel device or mechanism that has a fixed, non-flexible chute connected between the input side of the device and the output of the magazine. The fixed, non-flexible chute and associated conveyor brings individual rounds from a conventional storage magazine to the entrance of the device. The device has its entrance anchored to a fixed structure. The output end of the device, however, is designed to rotate with the weapon or weapon mount. While a flexible chute still is connected between the output side of the device and the firing weapon, that chute need be movable only in the elevation plane of the weapon. Three power inputs are used in connection with the invention. One input from the weapons's magazine correlates the input to the mechanism with the magazine feed rate. The exit power from the device is obtained from the weapon's demand. The third input is obtained from weapon mount rotation. Weapon mount rotation is used to adjust rounds within the device. This precludes the necessity of changing round position in either the fixed chute connected between the mechanism input and the magazine output or in the flexible chute connected between the output of the mechanism and the weapon.
The mechanism includes storage means and a differential for transferring rounds in the storage means. The differential adds and subtracts velocities to match the input velocity to the mechanism and the output velocity from the mechanism to the required weapon feed rate. By utilizing the storage capacity within the device, it is possible to permit the weapon to fire at full rate without requiring the magazine to match this rate in phase with the weapon. Consequently, reduced power is required to accelerate the magazine upon initiation of weapon operation. The elimination of chute motion about the azimuth plane permits the use of a fixed or rigid type feed chute for substantially the entire chute length, which in turn reduces cost in the overall system and provides increased reliability by elimination of potential jam or high friction points inherent in flexible chuting, caused by chute motion. The system described hereinafter also will allow the gun to cease fire while the reservoir provided in the mechanism absorbs ammunition and refills to a correct level before requiring the magazine to halt. This action again may be accomplished out of phase from the weapon.
One of the objects of this invention is to provide a simplified weapon system for a rapid firing weapon.
Another object of this invention is to provice means for correlating a rapid fire weapon demand rate for ammunition and the output rate of an associated magazine.
Another object of this invention is to provide a correlating device utilizing differential means for adjusting input and output velocities from the device.
Yet another object of this invention is to provide a correlating means mounted to and rotatable with a gun turret.
Yet another object of this invention is to provide a weapon system for a rapid fire gun having reduced power requirements for the drive of an associated magazine.
Other objects will be apparent to those skilled in the art in light of the following description and accompanying drawings.